The present invention relates to a refrigerator display case or cabinet with a ventilated glazed frame or surface and having a refrigerated chamber with a condenser and compressor positioned therebelow. The present invention finds particular and convenient, through not exclusive, application to refrigerator display cabinets for foodstuffs.
In the present state of the art, it is well-known that refrigerator display cabinets, having display windows that are internally cooled, tend to generate condensate on the corresponding external window surfaces, thus fogging the windows which thereby no longer are suitably transparent for display of contents within the refrigerated chamber. This is disadvantageous in display environments, such as shops or supermarkets, since the products inside the chamber are not clearly visible through the windows, consequently adversely effecting sales.
Many attempts to solve this problem have been made:
1. Through the use of an electrically operated heating element having a resistor, in most cases metallic, and placed in direct contact with the respective plate glass.
2. Through the use of "radiant glasses", i.e. electrically heated, through the insertion of electrical filaments into the plate glass.
3. Through external ventilation of the glazed surface by means of an air stream at ambient temperature sweeping across the external glazed surface.
The first two solutions are very extensive because they require high operating costs (electrical energy expenditure, resistors wearing out, etc.). The third solution, although obviating the higher operating costs for energy expenditure, results in an expenditure of energy by a supplemental fan and in the cost of the respective system. Furthermore, the anti-fogging effect is not very effective since the ventilated air also results in a condensate effect, though less than in a system totally without ventilation.